This invention relates to an ignition timing control device for an internal combustion engine and more particularly to an improved ignition timing control including a temperature responsive advance.
It is well known that a wide variety of internal combustion engines are now provided with electronic ignition control. The use of electronic circuitry permits a wider adjustment of ignition timing to suit a variety of different operating conditions. For example, it has been proposed to employ an engine temperature sensor in combination with the logic of the timing circuitry in order to provide additional spark advance for cold temperature starting. Normally, these devices would include a temperature sensor that is mounted in proximity to the engine so as to sense its temperature. This sensor then outputs a signal to a remotely positioned control circuit including a fire advancing circuit and will achieve an advance in the spark timing under cold starting conditions. Although such systems have advantages, there are some disadvantages with the proposed type of system as described.
For example, when the temperature sensor is remotely positioned from the ignition control circuit, it is necessary to provide a conductor to transmit the signal from the temperature sensor to the spark control circuit. In order to prevent noise and extraneous unwanted signals, it is desirable that the temperature sensor provide a high power output. However, with many engines such as outboard motors, there is not a battery as such and, hence, the temperature sensor cannot output large current signals under cranking operations. Furthermore, the disadvantages of the remote wiring should be readily apparent.
It is, therefore, a principal object of this invention to provide an improved, simplified and relatively compact ignition timing control device including a temperature sensor.
It is a further object of this invention to provide a temperature sensitive ignition timing control that is mounted as a complete unit on the engine.